Iran’s nukesIran’s Nuclear “Breakout” Time Reduced to 3-4 Months

Published 21 April 2020

In May 2018, when President Trump announced that the United States was withdrawing from the 2015 Iran nuclear deal, Iran “breakout” time was estimated to be 12-16 months. Breakout is defined as the time Iran would need to produce 25 kilograms of weapon-grade uranium (WGU), enough for a nuclear weapon. A new report says that Iran’s breakout time now is 3.1 to 4.6 months.

In light of a recent U.S. State Department arms control compliance report highlighting Iran’s growing “uranium enrichment activities and stockpile of enriched uranium,” the Institute for Science and International Security issued a report presenting recent Iranian breakout estimates and comparing them to pivotal historical ones.

“Breakout” is defined as the time Iran would need to produce 25 kilograms of weapon-grade uranium (WGU), enough for a nuclear weapon.

The report, written by David Albright and Sarah Burkhard, says that as of late February 2020, the breakout estimate is 3.8 months, with a range of 3.1 to 4.6 months. This estimate is based on an Institute breakout calculator, utilizing modified ideal cascade calculations, adjusted with results from an earlier multi-year program of complex computer simulations of Iranian breakout, conducted in collaboration with centrifuge experts at the University of Virginia, and supplemented by operational data on Iranian centrifuges.

The breakout estimates result from Iran’s installed enrichment capacity and its stock of low enriched uranium (LEU), as reported by the International Atomic Energy Agency (IAEA) in its quarterly reports on Iran. Albright and Burkhard note that a significant development is that Iran is at the threshold of having enough LEU to move from a four-step enrichment process to a three-step one, allowing a significant reduction of breakout times, a phenomenon referred to in the media as a “key threshold” or “enough LEU for a nuclear weapon.” A potential covert enrichment plant utilizing 3000 IR-2m centrifuges is also assessed, giving a breakout of 3.1 months.

The Annex to the report contains a summary of Iran’s stock of low enriched uranium, based on the IAEA’s most recent quarterly report on Iran, summarizing the situation as of late February 2020 and identifying which of the LEU stocks are used in the breakout calculations.

Here is the report’s Introduction:

If Iran decided to build nuclear weapons, it could use its existing, declared production-scale gas centrifuge plants, the Natanz Fuel Enrichment Plant (FEP) and the Fordow Fuel Enrichment Plant (FFEP), and low enriched uranium already produced there to make weapon-grade uranium, the key nuclear explosive material. It could also build a clandestine centrifuge plant, as it was doing in the past, where WGU could be produced without the knowledge of the International Atomic Energy Agency (IAEA) or Western intelligence.